Method and means for preventing excessive vibrations of speed responsive devices



March 22, 1932. E J. pANlsH 1,850,807

METHOD AND MEANS FOR PEEVENTING ExcEssIvE vIBRATIoNs oF SPEEDEEsPoN'sIvE DEVICES Filed April 14, 1924 /NVENTOR ERWIN JI PAN/SH BYMNGMATTORNEY f ylreitented Man-'22, .1932

Unirse srs Tiss Pnrrnnr orFllcE-j j Y ERWINJ. PANISH, on nmnsfnroncr;coivivnoTrona"V` METHOD' ,Aim MEANS non Y Application led'pril agovernorpand illustrating this invention as applied thereto. '7

sive device shown in Fig. 1.' l

Fg.v 3 is aaperspective ,view oi. meansfprovided. by the .presentinvention for absorbing .the impressedvibrations off the parts, and theprovision .of whichI have l'found to prevent squaringt or huntingl ofthe speedrespone sivedevice. v v .v

Figs is a perspective view of onemodifru cation ofthe device shown inFig. 3.

l Fig.. 5 is.. a longitudinal sectional View through vthersaiet'yjcollar andy sliding sleeve, showing the means. provided by therpresent invention for kabsorbing excessivey vibration.

. The speed-responsive device` shown in the accompanying drawings toillustrate one embodiment. of my invention comprises 1a-1no.tion-receiving member 10 in the form ofc an endless screw: This member10jmay bek formedV integral withga shaft 11, or it maybe 'a separatepartsecured' to a shaft or other r y motion-transmitting `meansxln anysuitable.

way. In the form herein shown,n the shaftj l1 forms part vof thespeed-responsive .device suoh'as a governorto control :the speed ofmechanism, or a speedometer ytoindicatet-he speed omechanism. i y

The `mass which isy moved inarotary path by themovement imparted tothe-shaft -11, and which has developed in it, the centrifu-V gal forceproduced .by such rotation, comprises a plurality of weights 12. In theform shown, theweights 412 are carried'by the de'- vice, for movementrelative 'to other parts of it,by bow-springs 13, having theirrespective and correspondingends 14, secured to a holder 15, preferablyin fthe. form ofa collar. The bow-springs 13 have their otherends y16secured to another'and independentsupport 17 having its faXis ofrotation coincident with `theaXis of rotation ot the .shatt'llr As amentsinY methods ot making kand oper-ating*y Fig-.2 is an'end view ofthe speed-respon.-

Vspeed-indicator, etc. f f

PREVENTING -nxonssrvnvnnerrrons or sr'nno nnsPoNsIvnnnv-tcns 1 f 1924;.'seriariNt. 706,242,i

matter of'fact, is usually preferable to have y the collar 17 in slidingengagementfwith the 'shaftlln The` bow-springs;.13 are formed tonormally take the shape shown in Fig.;1.

, Oneoithefcollars'l or 17 is .usuallyiixed vto the shaft 11,y (collar15 beingshown as so disposed), so thaty the rotarymovement 'of theyshaft maybe transmitted to thepweights 12. VThe other collar,in theillustrated form the collar 17 is connected to some annularv` member18,suclijas a braledisk'in case the n device is Vfen'iplo'yed asagevernor; or other annular part, in case the device is used as a Therotation of the parts, develops .in the Y weights a centrifugalorcewhichcauses the `weights. to be thrown outwardly, detorming .thebowspringsv13 andk shortening the recti-` linear distance between theirrespective ends. A'Ihis' pulls the collarlwith'its connected annularmember 18 towardthe collar 15 'fas tened to the shaft 11 andproducesafrelative movement longitudinally between the vshaft and .the annularmember. .l

TheA speed of rotation, of course, deterf mines the amount fofVcentrifugah force del* veloped; and this, in turn,` determines theextent ot relativelmovement b `etweenthe shaft 11' andtheannularmemberlS. o Y

In `the case of agovernor having Yan annular member inthe form of a:brake disk, the

.latter cooperates with a brake-shoe 18l for applying tothe partsanza'ction opposing rotation, which action keeps the parts rotatingk ata'predeterminedspeed according to the setting of the' brake-shoe. This4'setting is'Y variable for the purpose of allowing variations in thepredeterminedspeed.

kIn'the case ot'za lspeed-'ndicatingfdevice, the annular member `1t?) isVsuitably connected to' indicating means, such as a scale andpointe'rl'or a graduated ld-rum,toindicateaccording to n a predetermined plan,either the variationsof i speed change'sortherate of speed or both.

- Under` normal circumstances, a device of the type herein shown, whenusedk as a gover-V nor,operates by varying the load, kor in other words,the amount of power absorbed by the friction produced betweenthe annularmember 18 and the brake-shoesk For instance, 1

' seen from the side.

vshould the torque applied to the shaft 11 increase appreciably, eventhough slightly with its tendency to increase the speed of rotation ofthe weight-members 12, the resulting increase in speed will momentarilyincrease the centrifugal force developed in the weightmembers A12, witha tendency to further draw the collar 17 toward the collar 15. But, itmust be remembered, the annular member 18 is in engagement with thebrake-'shoe and, with its, connected collar 17, is .held against suchlongitudinal movement. The result is that the bow-springs 13 are furtherdeformed in away which does notproduceany shorten` ing of the lineardistances between their respetive ends, 'for instance, in wave'form'asTherefore, the excess torque is absorbed 'by the deformation oftihebow-springs and also by the increased Yfriction between the disk andthe lbrake-shoe.

How, if the 'torque is decreased slightly, the

bow-springs tend to assume 'the shape they had, before the speed wasincreased, that is, straight; with coincident change of position of theweight-member. It will thus be seen that, Without producing any relativemove- 'ment between the collar 17 carryingthe annular member 18 and thecollar 15, the weight-members 12 oscillate in their plane of rotation inthe continuous effort of the governor to 'maintain its speed, kandrconsequently thespeed of its connected parts, conetant. Theseo'scillationsfhave a certain frequency, depending'upon'thespeed-variations.

These 'natural oscillations arev inherent in the proper functioning ofthe ygovernor and are usually so minute, lin the ordinary variation oftorque appliedwto the shaft 11, as to be practically unnoticeable.

In manufacturing kgovernors' of the ytype illustra'techit h'asbeenfound,` at times, that are faulty in that they square or hunty'aidthis'is truelin` spite of the utmost care taken in their manufacture.yThis squaring or hunting ymaybe character- "ized as excessivevibrationor yoscillation of 'the governor parts,

and is usually observable by a knocking 'noise produced' in the yrapidlongitudinal oscillation of theannular member 18.

Inthe case of a governor, squaring renders rvthe device 'inoperative assuch,.and upsets the predetermined plan ofnspeed-control. in addition fto the sometimes objectionable noise itproduces. Apeculiarsphase of thesquaring fproblem is Ythat a tendencyfor a governor `tri/square cannotbe.' determined *or detected by superficial inspectionof the same. yItonly can'be done afterthe' governor is installed in the machineormecbanism in whichitV isintended to operate. Even thon,

some; governors have been 'found to square "when the parts vhave beenbrought to one speed, and not'to square when the parts have "been'brought 'to' another speed. Then,

ywithout my invention @applied thereto, over yhave-led me to believethat this squaring is produced by vibrations being impressed upon thenaturally vibrating governor Weightmembers, which, as above stated, arevibrating or oscillating in their proper operation.

f I have found that impressed vibrations do not always cause sguaringandthis had led vme to believe'that squaring .occurs only when theimpressed vibrations have substantially 'the *same ratio of frequency asthe natural vibrations, causing the amplitude of the naturalvibrationsito' lm magnified, by resonance. c The Vexcessive `vibrationsof the weightmembers 12,'in'theoase of a governofncaxse theannularfmember 18 to oscillate to and from Ktheqpofsition where it is engagedbythe brake-shoe. This of course, upsets the natural 'functioning of thegovernor so that it is useless for its purpose. f

I have'found thatfthe excessive vibrations kofthe weight-members. :12and connected yparts :can lbe v'prevented lby applying friction -or,inother words,abrakmgaction opposing `movement of the imeans vsupporting'the springs at one end namely, the collar 17 and yannularn iefmber 18,with relation to the means supporting the springs at their other endsnamely, 'the'collar 15. In the formherein ilylustrateh thisfriction isappliedby means of 'aspringlQ secured at20 to a collar 21, fixed uponthe shaft 11 by means of a set-screw 22.

The'spring 119 is made'to'bear againstasleeve 23carried bythe'collar 17.W henthis friction-hais fbeen applied 'to ythe governor parts. such asby the spring 19 shown'in Fig. 1, it `is found that lthe governor willnot square even when vibrations of extra ordinary amplitude areimpressedupon the yweight-members 12. 'Inthemauufacture vof governors, in-allYrespects like the onevherein shown, except 50% of the governorsxmadewere found to square 'Withk thesame governor and Vmy "inventionembodiedtherein, squaring has beenelimin'atedg'it ceases to bezapmblem.

The mode offoperaton'of agovernor'embodyingimyinventionyas Iunderstandrit is.

that the ffriction produced by the springs 1!) opposes any excessiveoscillation 'of the collar 17 with' thefannulan member '158 byabsorbingy fthe energy tending' to produce the: same.

It must `be understood however, that any statement as tomode ofoperation or'theory herein contained is merely by way of explanation,and that I am not to be confined to suchy statements.k The fact is, thatthe application :of this friction prevents squaring, whatment is by nomeans critical. This adjustment may be accomplished byv deforming thespring 19 to increaseits pressurefupon the sleeve 23 or itmaybeperformed byy a separate adjusting mechanism such `as a screw 26,V

mounted in the collarj21 andengagingzthe spring 19.

theV friction producingldevice shown in the otherv figures. In thisform, a pair of springs vare provided to enga-ge each side of the sleeve23. The. operation of this form ofdevice is substantially identical withthat shown in the other form, the only difference being that the springmay be shorter than that shown in Figs. 1,12 and 3. v

p In the drawings, the spring is mounted on the collar 21 in a slotadapted ftoreceive it. The spring 19is fastened in place in the slot inthe collar 21 byv pressing over the material at the tops of the walls ofthe slot. Any other suitable fastening yarrangement may be provided. Q

The sleeve 23 connected to the collar 17 is extended toward the collar21 so that the end 24 of the sleeve 23 will engage `the wall 25 ofthecollar 21 to constitute a safety device by limiting the inwardvmovement of the collar 17 and annular member 18 to prevent damage.being done to the springsv 13, should-the brake-shoe fail tooperate.vThe adjusted position of the collar21 determines the maximum movementofthe parts. Y Having now describe ll the invention, what l is claimedas new and for which itis desired to obtain Letters Patent, is: Y

' 1. In combination, a sneed-responsive de-l vice having la revolubleshaft; a member revolving with the shaftvand slidable longitu-vcentrifugallyy operated means g means carrying 4the latter and inter--connecting the shaft and saidslidable memrdinally thereon;

ber forcausingsaid` member to slide on said shaft; and frictionaly meanssecured to the shaft and tending t'o brake the longitudinal Y.

berfor causing said member to slide on said sliding movement of saidmember.`

2. A ,speed responsive device having a shaft.; aslide thereon; weights;means carrying the latter and interconnecting the shaft and said slide`Yfor causing said slide to `moveonzthe shaft when the weights moveoutwarddue to centrifugal force; safety means en- In Figa there is shown4a modification of dinally thereon;

gages 'by the ygaat `for Lunsung its `Sliding movement;and'means carriedby said safety 'means-for frictionallyengaging the slide to, apply abrakingiaction ropposingits movement. l c

' 3.- A i speed 'responsive' .device having av shaft; a slide thereon;weights';means carryingwthe, latterV and interconnecting the. shaftandsaid slide for causingfsaid slideto move'- on the shaft when theweights'moveoutwardly due tocentrifugal force ;la stop adapted to l n`be engaged bythe slide for positively limit- 1 ing its slidingmovement; and means carriedy Y f by said stop for slidably engaging theslidel in all its positions to yieldingly oppose its sliding movement. g

shaft r;A a part slidably mounted onthe shaft.;

l means interconnecting they shaft and the sliding part; weights carriedby saidmeansy and 41A speed responsivek device having' -a shaftfrotates;a collar secured to the shaft" to turn therewithy and` with relation towhich the sliding part moves; and means' secured to the collar andyieldingly engaging the slidingpart to yapply a braking action` opposingits sliding movement. c

5. A speed responsive device'having a shaft; a part slidably mounted onthe shaft;

means interconnecting the shaft and the sliding partgweights carried bysaid Vmeans and adapted to cause relative movement between the shaft andsaid sliding part when the shaft i rotates;.a collar secured to theshaft to turn therewith and with relation to which the sliding-partmoves; and a leaf 4spring secured to ing part. c

6. A speed responsive device havinga shaft; a collar secured to theshaft; a sleeve movable onV the shaft in the direction 0f the securedcollar; weights; supporting membersy for the weightsconnected to thecollar for Y rotation therewith and connected to the sleeve to slideythe same on the shaft with relation to s the 'collar `when the weightsmovefoutwardly shaft; kand frictional means between the shaft andslidable member to brake the longitudinal sliding movement of themember.

' 8. Inl combination, a;speedresponsive de-v4 vice. having a revolubleshaft; a member revolving with'the shaft and slidable longituthe collarand yieldingly engagingthe slidc Vif n Lemmi dnally thereon;centrifugally operated Y means; means Carrying the latter andinterconnecting the shaft and said. slidable memberfor causing saidmember toslide on said f' 5 shaft; and a leaf spring between said shaftand slidable member to brake the longitudinal sliding movement of saidmember.

Signed at Bridgeport, in the county of Fairfield, and State ofConnecticut, this 12th 10 day of April A. D. 1924.

ERWINy J. PANISH.

